Phase I/II rand. ABT-378 dose-blinded, mlti-ctr study of ABT-378/ritonavir in comb. w/stavudine (d4T) & lamivudine (3TC) in otherwise hlthy HIV-inf. males/fem Primary obj. - assess the safety, tolerability and antiviral act. of ABT-378/ ritonavir when adm. orally in antiretroviral naive HIV-inf. pat. Secondary obj. 1) to determine steady-state pharmacokinetic profile of ABT-378/ritonavir in antiretroviral naive HIV-inf. pats. 3)to assess the relationship between ABT-378 /ritonivir and HIV RNA decay profiles in antiretroviral naive HIV-inf. patients.